Evaluation of substrates for mycorrhization and weaning of two micropropagated grapevine rootstocks

Abstract

The aim of this work was to select substrates conductive to the establishment of arbuscular mycorrhizas in the production of micropropagated grapevine rootstocks. Micropropagated SO4 and Paulsen 1103 rootstock plantlets were weaned for three weeks in trays with mycorrhizal fungal- inoculated or uninoculated substrates (prepared with soil, compost, calcined rice hulls, vermiculite and sand, besides a commercial substrate). At the end of the weaning period and ten weeks after, shoot and root growth and mycorrhizal root colonization were evaluated. Mycorrhizal root colonization varied according to the rootstock and substrates, with a significant interaction between these factors. The commercial substrate was associated with the highest increase in shoot and root mass, but it decreased mycorrhizal colonization. The best substrate for Paulsen 1103 rootstock growth and mycorrhizal inoculation was prepared with soil, compost and sand and, for the SO4 rootstock the substrate prepared with soil, compost and vermiculite.